Indices of prime values of heptanacci-Lucas numbers A104621.

Terms

a(0) =0a(1) =2a(2) =3a(3) =5a(4) =7a(5) =10a(6) =17a(7) =24a(8) =25a(9) =26a(10) =28a(11) =38a(12) =40a(13) =49a(14) =62a(15) =79a(16) =89a(17) =114a(18) =140a(19) =145a(20) =182a(21) =248a(22) =353a(23) =437a(24) =654a(25) =702a(26) =784a(27) =921a(28) =931a(29) =986